Music and Sound Effects (SFX)
Film and broadcast studios rely on collections of sound effects to bring their productions to life. In the past, these collections were housed on CDs with a database that would be available to track down the sounds among dozens of discs. More recently collections have gone online with a more user friendly subscription model. One the of the largest of these has been the massive BBC collection. British Broadcasting Corporation (BBC) has produced countless hours of radio content that includes thousands of hours of radio plays where voice and sound effect were used to convey all of the drama of a particular scene. Studios would have paid thousands of dollars for this resource on disc or tied into a subscription from BBC or one of their competitors.
The BBC has made a subset of their archive available free for educational usage. This means you can access thousands of SFXs for your productions as long as you are creating a non-commercial production.
NOTE: The website is in Beta but it is live. I found I had to reload the page a few times before all of the assets showed up. It's worth the trouble. Use the search feature to narrow down the list.